Rule History

alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE BPFDoor CnC Domain in DNS Lookup (ntpussl .instanthq .com)"; flow:established,to_server; tls.sni; bsize:21; content:"ntpussl.instanthq.com"; fast_pattern; reference:url,rapid7.com/blog/post/tr-new-whitepaper-stealthy-bpfdoor-variants/; classtype:trojan-activity; sid:2069139; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2026_05_04, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2026_05_04;)